2020년 4월 20일 (월) 오후 5:42, Christian König <christian.koenig@xxxxxxx>님이 작성: > > Am 20.04.20 um 09:59 schrieb js1304@xxxxxxxxx: > > From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> > > > > Until now, PageHighMem() is used for two different cases. One is to check > > if there is a direct mapping for this page or not. The other is to check > > the zone of this page, that is, weather it is the highmem type zone or not. > > > > Now, we have separate functions, PageHighMem() and PageHighMemZone() for > > each cases. Use appropriate one. > > > > Note that there are some rules to determine the proper macro. > > > > 1. If PageHighMem() is called for checking if the direct mapping exists > > or not, use PageHighMem(). > > 2. If PageHighMem() is used to predict the previous gfp_flags for > > this page, use PageHighMemZone(). The zone of the page is related to > > the gfp_flags. > > 3. If purpose of calling PageHighMem() is to count highmem page and > > to interact with the system by using this count, use PageHighMemZone(). > > This counter is usually used to calculate the available memory for an > > kernel allocation and pages on the highmem zone cannot be available > > for an kernel allocation. > > 4. Otherwise, use PageHighMemZone(). It's safe since it's implementation > > is just copy of the previous PageHighMem() implementation and won't > > be changed. > > > > I apply the rule #4 for this patch. > > > > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> > > Reviewed-by: Christian König <christian.koenig@xxxxxxx> for the TTM > changes, but I can't judge if the general approach makes sense or not. Thanks for review! General approach needs to get an agreement from more developers. Thanks.
